I'm feeling Lethality a lot more than Concealment. Something about poisons and dotspecs really feels nice, you buildup and then just dump TAs into things, as many as you can. It's got a surprising amount of survivability for a stealth class and proc'ing Kolto Infusion on your roll lends really well to a sort of in-and-out skirmishing playstyle. It's very easy to get into trouble, but (barring electronet ) it's very easy to get out of trouble.
Problem is, well, it kinda sucks in PvP. You need at least two, more like four GCDs to run a full setup before you can start dumping damage. That means you need to bite and hold, setting up on a guy and sticking to him, but with heals, snares and physics everywhere, staying committed to a single target is...iffy. Particularly heals; heal/sec directly negates damage/sec, and Lethality thrives on damage/sec.
So, what's the niche? Generously spreading DoTs in teamfights on the middle? Harassing healers or RDPS in same? Using skirmishing and self-heals to defend or harass a side objective?
